Toilets, Sinks, Showers, Tubs and Disposals - Thudding in pipes all of a sudden?

I turned on the hot water in my bathroom sink one day, and if you turn the handle past a certain point, the pipes thud and rattle (more thudding than rattling) thru the whole house it seems...it's a horrible sound, does anyone know why it's happening and how to fix it??! Thanks!! -- the cold water doesn't do it, just the hot and just in that sink...weird to the untrained eye-- I'm hoping it's something someone has seen and can help with

Replace the stem or cartridge. Some part of the stem or cartridge is worn or loose, which causes vibration.

I'm confused tho -- the faucet set is new, about three months old...and the thudding isn't in the faucet itself, it sounds like it's further down...the whole fixture shakes when it happens -- not sure if that helps or makes helping harder... :o